This invention relates to the field of wound dressings and bandages.
U.S. Pat. No. 4,655,210 describes a polyurethane foam bandage which is said to provide certain advantages over the common strip bandage including greater wound exudate-carrying capacity, better protection of the wound site from contusion or other pressure trauma and greater moisture vapor permeability in its adhesive tab portions. The bandage is manufactured from a single liquid-permeable foamed polyurethane sheet possessing a liquid-permeable porous pressure sensitive adhesive layer on its skin-contacting side. Selected areas of the sheet are heat compressed to provide first and second wound site-securing tab portions on each side of a foamed pad portion which has not been subjected to compression. Both the tabs and the pad provide ready absorption and transfer of fluids from the wound site. When the pad approaches its maximum wound exudate-carrying capacity, the tabs wick excess exudate.
Were wound exudate-carrying capacity the sole or principal consideration in the construction of an effective wound dressing, the foam bandage of U.S. Pat. No. 4,655,210 could be said to possess an advantage over the aforementioned common strip bandage whose adhesive tab portions are incapable of wicking wound exudate. However, at least as important, if not more important, than a high wound exudate-carrying capacity is the ability of a wound dressing to adhere to the site of application throughout the entire period of its expected functional life. A premature loss of adherency will require more frequent application of fresh bandages and consequently, a greater cost to the consumer. The very ability of the tab portions of the bandage of U.S. Pat. No. 4,655,210 to wick excess wound exudate is itself a disadvantage where long term adherency is concerned. Thus, once wound exudate makes contact with the adhesive layer, it begins to infiltrate the adhesive compromising the adherency of the bandage to the skin.